复合酶与复合酶菌制剂对日粮体外降解率及不同泌乳阶段奶牛产奶性能的影响

Effect of Compound Enzyme and Compound Enzyme Probiotics Preparation on Degradation Rate of Diet in vitro and Milk Production Performance of Dairy Cows at Different Lactation Stages

本试验旨在研究复合酶及复合酶菌制剂对奶牛日粮体外降解率及不同阶段奶牛产奶性能的影响。在体外试验中,分别以基础日粮(Ⅰ组)及基础日粮中分别添加复合酶制剂(Ⅱ组)、复合酶菌制剂(Ⅲ组)的日粮作为发酵底物,体外培养72 h,测定不同时间点(6、12、24、36、48、72 h)日粮干物质降解率(DMD)和粗蛋白质降解率(CPD)。在饲养试验中,分别选取体重、胎次、体况相近的泌乳前期(30 d±5 d)、泌乳中期(100 d±5 d)和泌乳后期(250 d±5 d)奶牛各24头,平均分成3组,其中对照组(Ⅰ组)奶牛饲喂全混合日粮(TMR),复合酶制剂组(Ⅱ组)和复合酶菌制剂组(Ⅲ组)奶牛在TMR中分别添加1 kg/t的复合酶制剂和复合酶菌制剂。每期试验持续74 d,其中预试期14 d,正试期60 d,每天记录产奶量。结果显示:①体外试验中,Ⅱ、Ⅲ组的DMD、CPD均随处理时间的延长而增加。在各个时间点,Ⅲ组的DMD、CPD均高于Ⅱ组,其中DMD在6、72 h时差异显著(P<0.05),CPD在36、72 h时差异显著(P<0.05),在其他时间点差异均不显著(P>0.05)。②在泌乳前期,Ⅱ、Ⅲ组的平均日产奶量与Ⅰ组相比分别提高了3.68%和4.10%,差异显著(P<0.05),Ⅱ、Ⅲ组之间差异不显著(P>0.05);泌乳中期,Ⅱ、Ⅲ组的平均日产奶量与Ⅰ组相比分别提高了7.53%和10.66%,差异显著(P<0.05),Ⅱ、Ⅲ组之间差异不显著(P>0.05);泌乳后期,Ⅱ、Ⅲ组的平均日产奶量与Ⅰ组相比分别提高了7.06%和5.16%,差异显著(P<0.05),Ⅱ组、Ⅲ组之间差异不显著(P>0.05)。综上,复合酶与复合酶菌制剂均能在一定程度上提高日粮体外DMD和CPD以及奶牛在不同时期的产奶量,其中,复合酶制剂对提高泌乳后期奶牛产奶量效果更好,复合酶菌制剂对提高泌乳中期奶牛产奶量效果更好。

The purpose of this experiment was to study the effect of compound enzyme and compound enzyme bacteria preparation on the degradation rate of diet in vitro and milk production performance of dairy cows at different lactation stages.In in vitro experiment,the basic diet(groupⅠ)and the basic diet added with compound enzyme(groupⅡ)and compound enzyme probiotics preparation(groupⅢ)were used as fermentation substrate respectively.After 72 h of culture in vitro,the dry matter degradation rate(DMD)and crude protein degradation rate(CPD)of the diet were measured at different time(6,12,24,36,48 and 72 h).In feeding experiment,24 dairy cows with similar body weight,parity and condition were divided into three groups at early lactation(30 d±5 d),middle lactation(100 d±5 d)and late lactation(250 d±5 d),respectively.The cows in control group(groupⅠ)were fed with TMR,in compound enzyme group(groupⅡ)and the compound enzyme probiotics group(groupⅢ)were fed with the TMR added with 1 kg/t compound enzyme and compound enzyme probiotics respectively.The trial period was 74 days,including 14 days of pre trial period and 60 days of normal trial period.`The results showed that:①In vitro DMD and CPD of the two groups increased with the prolongation of treatment time.At each time point,the values of DMD and CPD in groupⅢwere higher than those in groupⅡ,the difference of DMD was significant at 6 and 72 h(P<0.05),CPD was significant at 36 and 72 h(P<0.05),and there was no significant difference at other time points(P>0.05).②In the early stage of lactation,the average daily milk production of groupsⅡandⅢincreased by 3.68%and 4.10%respectively compared with groupⅠ,the difference was significant(P<0.05),and the difference between groupsⅡandⅢwas not significant(P>0.05).In mid-lactation,the average daily milk production of groupsⅡandⅢincreased by 7.53%and 10.66%respectively compared with groupⅠ(P<0.05),and the difference between groupsⅡandⅢwas not significant(P>0.05).In the later stage,the average daily milk production of groupsⅡandⅢincreased by 7.06%and 5.16%respectively compared with groupⅠ(P<0.05),and the difference between groupⅡandⅢwas not significant(P>0.05).In conclusion,both compound enzymes and compound enzyme probiotics preparations could improve the in vitro DMD and CPD of the diet and the milk production of dairy cows in different periods to a certain extent.Among them,the compound enzyme preparation had a better effect on increasing milk production of dairy cows in the late lactation,while the compound enzyme probiotics preparation has a better effect on increasing milk production in mid-lactating dairy cows.